Recently several articles and patents have been published relating to the use of cyclodextrin in plant protecting formulations [Novenyvedelem, 19, 364 (1983); J. Szejtli: Cyclodextrins and their Inclusion Complexes, Akademiai Kiado, Budapest, 1982]. On forming complexes of molinate (S-ethyl-N,N-hexamethylene-thiocarbamate), bentiocarb (S-4-chlorobenzyl-diethylthio carbamate) and dichlorphos (2,2--dichlorovinyl-dimethyl-phosphate) the volatility of the active ingredient is significantly decreased and the activity of the pesticide remains sufficient for a longer period of time [Mikasa Chemical Industrial Co; KOKAI No. 80.81806; DOS No. 2,422,316 (1974); Acta Chem. Acad. Sci. Hung. 107, 195 (1981)]. Methyl-parathion (0,0-dimethyl-0-4-nitrophenyl-phosphorothioate) and natural pyrethrines and pyrethroides, respectively, are converted into the cyclodextrin A 3673/77-OE complexes in order to increase the stability against light and oxygen to a considerable extent [Pestic. Sci. 11, 134 (1980); U.S. Pat. No. 3,846,551 (1974);Nippon Noyaku Gakkaishi 1, 41 (1976); 2, 41 (1977)]. The dichlobenyl (2,6-dichloro-benzonitrile) active ingredient easily sublimates and on standing the granulated product sticks together; this can be inhibited by forming complex with cyclodextrin [5th Int. Cong. Pesticide Chem. (IUPAC) Kyoto (1983)].
The complex formation of 2-chloromethane-phosphonic acid with cyclodextrin results in the fact that on contacting with plant tissue the ethylene release is a long-lasting process and this is more efficient than the delivery of ethylene from a very promptly acting active ingredient [Acta Chim. Acad. Sci. Hung. 107, 231 (1981)].